The present invention relates to methods for fabricating a plated product that has a base on which a basecoat layer, a metal plating layer, and a topcoat layer are formed, and, more particularly, to methods for fabricating a plated product that has microcracks formed in a metal plating layer to suppress corrosion development in the metal plating layer, thus maintaining the appearance of the product.
For example, Japanese Laid-Open Patent Publication No. 10-309774 describes a method for fabricating a layered body with a silver plating layer. The layered body includes a base, an undercoat layer, the silver plating layer, and a topcoat layer. The undercoat layer is formed by drying an undercoat agent, or a varinish that contains alkoxy-titanium-ester and at least either a silane coupling agent with epoxy radicals or epoxy resin.
To form the layered body, the undercoat agent is applied to the surface of the base and is dried to obtain the undercoat layer. Subsequently, an aqueous solution of silver is applied to the surface of the undercoat layer and is dried to form the silver plating layer. The topcoat layer is then formed on the surface of the silver plating layer. The method of the aforementioned patent publication is applicable to layered products with various bases such as insulating or conductive bases. Further, as fabricated by this method, the layered body has the silver plating layer and the undercoat layer that are securely bonded together, and the durability of the layered body is improved. That is, the method makes it possible to efficiently and easily fabricate a layered body that has a silver plating layer with an improved property.
However, the layered body does not include a structure for preventing the topcoat layer and the silver plating layer from being corroded. Thus, if a chloride ion (Clxe2x88x92) from the exterior of the layered body enters the silver plating layer through the topcoat layer, the material of the silver plating layer, or silver, is corroded. Once the corrosion occurs, the corrosion develops to the entire silver plating layer, thus forming visible whitish lines in the silver plating layer. This significantly hampers the appearance of the layered body. The layered body is thus highly unlikely to pass a salt water spraying test or CASS(Cupric chloride, acetic Acid, Salt Spray) Test for estimating anti-corrosion resistance and anti-weather resistance of a plated product used as an ornament.
Accordingly, to solve the aforementioned problem, it is an objective of the present invention to provide a method for fabricating a plated product that prevents the appearance of the product from being hampered by corrosion of a metal plating layer and passes an anti-corrosion resistance test.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, the invention provides a method for fabricating a plated product with a basecoat layer, a metal plating layer, and a topcoat layer that are formed on a surface of a base. The method includes the steps of forming the basecoat layer and the metal plating layer on the surface of the base, forming a microcrack in the metal plating layer by subjecting the metal plating layer to a cold heat treatment or a supersonic wave treatment after the formation of the basecoat layer and the metal plating layer, and forming the topcoat layer on a surface of the metal plating layer.
A further perspective of the present invention is a method for fabricating a plated product with a basecoat layer, a metal plating layer, and a topcoat layer that are formed on a surface of a base formed of synthetic resin. The method includes the step of forming the basecoat layer on the surface of the base. The basecoat layer is obtained by applying a basecoat agent to the surface of the base or immersing the surface of the base in the basecoat agent and then drying the basecoat agent on the surface of the base. The method also includes the step of forming the metal plating layer on the basecoat layer. The metal plating layer is obtained by a chemical silver plating method. The method further includes the steps of forming a microcrack in the metal plating layer by subjecting the metal plating layer to a cold heat treatment or an ultrasonic wave treatment, and forming the topcoat layer on the surface of the metal plating layer.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.